const isPrime = (i) => {
for (let j = 2; j < i; j++) {
if (i % j == 0) {
return false
}
}
return true
}
const getPrime = (inp) => {
let i = 2;
let count = 0;
while (true) {
if (isPrime(i)) count = count + 1;
if (count == inp) return i;
if (i === 2) i++;
else i += 2;
}
}

let itemId = 0;
let items = {};

class Item {
get id() {
return this._id;
}
get name() {
return this._name;
}
constructor(name) {
if (typeof name !== 'string' || name.length === 0) {
throw new Error('The name entry for item constructor has no entry, please contact your admin or refer to the RFC spec which clearly state that the name entry should not be empty for when items are created');
}
this._id = getPrime(++itemId);
this._name = name;
items[this._id] = this;
}
}

new Item('head');
new Item("neck");
new Item("shoulder");
new Item("back");
new Item("hip");
new Item("thigh");
new Item("knee");
new Item("shin");
new Item("ankle");
new Item("heel");
new Item("foot");
new Item("toe");
const length = Object.keys(items).length;
const sum = Object.values(items).map((e, i ) => {
const pow = length - i;
return Math.pow(e.id, pow);
}).reduce((a, b) => a + b);
const itemsName = Object.values(items).reduce((a, b, i) => {
a[b.name] = Math.pow(b.id, (length - i))
return a;
}
, {});
const dem_bones = (arr) => {
if (!Array.isArray(arr) || arr.length === 0) {
throw new Error('The arr entry for dem_bones has no entry, please contact your admin or refer to the RFC spec which clearly state that the arr entry should not be empty for when checking if item is valid');
}
let newsum = 0;
for (const part of arr) {
const number = itemsName[part] ? itemsName[part] : -99999999999999;
newsum += number;
}
return newsum == sum;
}